{"id":1160,"date":"2026-09-28T03:39:52","date_gmt":"2026-09-28T03:39:52","guid":{"rendered":"https:\/\/wdlvalve.com\/?p=1160"},"modified":"2026-09-28T03:39:52","modified_gmt":"2026-09-28T03:39:52","slug":"%d8%af%d9%84%d9%8a%d9%84-%d8%b5%d9%85%d8%a7%d9%85-%d8%a7%d9%84%d9%83%d8%b1%d8%a9-%d8%a7%d9%84%d9%85%d8%a8%d8%b1%d8%af-%d8%b0%d9%8a-%d8%a7%d9%84%d9%85%d8%af%d8%ae%d9%84-%d8%a7%d9%84%d8%ac%d8%a7%d9%86","status":"publish","type":"post","link":"https:\/\/wdlvalve.com\/ar\/%d8%af%d9%84%d9%8a%d9%84-%d8%b5%d9%85%d8%a7%d9%85-%d8%a7%d9%84%d9%83%d8%b1%d8%a9-%d8%a7%d9%84%d9%85%d8%a8%d8%b1%d8%af-%d8%b0%d9%8a-%d8%a7%d9%84%d9%85%d8%af%d8%ae%d9%84-%d8%a7%d9%84%d8%ac%d8%a7%d9%86\/","title":{"rendered":"\u0635\u0645\u0627\u0645 \u0643\u0631\u0648\u064a \u0645\u0628\u0631\u062f \u0630\u0648 \u0645\u062f\u062e\u0644 \u062c\u0627\u0646\u0628\u064a \u0644\u0627\u0633\u062a\u062e\u062f\u0627\u0645\u0627\u062a \u0627\u0644\u063a\u0627\u0632 \u0627\u0644\u0637\u0628\u064a\u0639\u064a \u0627\u0644\u0645\u0633\u0627\u0644: \u062f\u0644\u064a\u0644 \u0627\u0644\u062a\u0635\u0645\u064a\u0645 \u0648\u0627\u0644\u0627\u062e\u062a\u064a\u0627\u0631"},"content":{"rendered":"
\n
\n

A side entry cryogenic ball valve for LNG service<\/strong>
\nuses a two-piece or three-piece body, low-temperature materials
\nand an extended stem to provide reliable quarter-turn isolation
\nat temperatures down to \u2212196\u00b0C. Correct seat design, body-cavity
\nrelief and cryogenic testing are essential because trapped LNG
\nexpands rapidly when it warms.<\/p>\n<\/header>\n


\n\"WDL
\n<\/a>
WDL Side Entry Cryogenic Ball Valve for LNG and low-temperature
\nprocess isolation.<\/figcaption><\/figure>\n
\n

What Is a Side Entry Cryogenic Ball Valve?<\/h2>\n

A side entry cryogenic ball valve is assembled through body
\nsections that split across the pipeline axis. The construction
\nmay use two or three main body pieces. This arrangement provides
\na practical combination of pressure containment, manufacturing
\nflexibility and access to the ball and seats during workshop
\nmaintenance.<\/p>\n

The extended stem places the packing, operator and actuator above
\nthe cold zone and pipe insulation. This limits heat transfer
\ntoward the process and helps the stem packing remain at a
\ntemperature where it can continue sealing effectively.<\/p>\n<\/section>\n

\n

Why Does LNG Service Require a Special Valve Design?<\/h2>\n

LNG is normally handled near \u2212162\u00b0C. At this temperature,
\nordinary valve materials, seals and lubricants may contract,
\nharden or lose toughness. A valve that works at ambient
\ntemperature may develop seat leakage, excessive torque or
\nstem-seal problems after cooling.<\/p>\n

A cryogenic LNG valve must therefore account for thermal
\ncontraction, low-temperature material toughness, heat transfer,
\nbody-cavity pressure and repeated cooling and warming cycles.
\nThe final design should be based on the minimum design
\ntemperature rather than only the normal operating temperature.<\/p>\n<\/section>\n

\n

Two-Piece vs. Three-Piece Side Entry Construction<\/h2>\n
\n\n\n\n\n\n\n\n\n
\u0646\u0642\u0637\u0629 \u0627\u0644\u0627\u062e\u062a\u064a\u0627\u0631<\/th>\nTwo-Piece Body<\/th>\nThree-Piece Body<\/th>\n<\/tr>\n<\/thead>\n
Construction<\/td>\nMain body plus one body connector<\/td>\nCentral body with two end connectors<\/td>\n<\/tr>\n
Body joints<\/td>\nFewer split-body joints<\/td>\nMore assembly flexibility<\/td>\n<\/tr>\n
Maintenance<\/td>\nUsually serviced after removal or workshop access<\/td>\nThe center section may be easier to remove in suitable
\npiping layouts<\/td>\n<\/tr>\n
Selection basis<\/td>\nPressure, size, leakage risk and project standard<\/td>\nMaintenance strategy, piping layout and project standard<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

Neither arrangement is automatically better for every LNG
\nproject. The correct choice depends on valve size, pressure
\nclass, piping loads, available maintenance space, testing
\nrequirements and the owner\u2019s maintenance strategy.<\/p>\n<\/section>\n

\n

WDL Side Entry Cryogenic Ball Valve Range<\/h2>\n

WDL Valve publishes the following reference range for its
\n
\n\u0635\u0645\u0627\u0645 \u0643\u0631\u0648\u064a \u0645\u0628\u0631\u062f \u0630\u0648 \u0645\u062f\u062e\u0644 \u062c\u0627\u0646\u0628\u064a \u0645\u062e\u0635\u0635 \u0644\u0627\u0633\u062a\u062e\u062f\u0627\u0645\u0627\u062a \u0627\u0644\u063a\u0627\u0632 \u0627\u0644\u0637\u0628\u064a\u0639\u064a \u0627\u0644\u0645\u0633\u0627\u0644
\n<\/a>.
\nFinal ratings and dimensions must be confirmed on the approved
\nproject drawing.<\/p>\n

\n\n\n\n\n\n\n\n\n\n\n\n\n
\u0627\u0644\u0639\u0646\u0635\u0631<\/th>\nPublished WDL Specification<\/th>\n<\/tr>\n<\/thead>\n
Size range<\/td>\nDN25\u2013DN600 \/ NPS 1\u201324<\/td>\n<\/tr>\n
Body construction<\/td>\nTwo-piece or three-piece side entry body<\/td>\n<\/tr>\n
\u0648\u0635\u0644\u0627\u062a \u0627\u0644\u0623\u0637\u0631\u0627\u0641<\/td>\nFlanged, threaded, socket weld or butt weld, subject to
\nvalve size and project requirements<\/td>\n<\/tr>\n
Face-to-face<\/td>\nASME B16.10 or project-specified standard<\/td>\n<\/tr>\n
\u0646\u0637\u0627\u0642 \u062f\u0631\u062c\u0627\u062a \u0627\u0644\u062d\u0631\u0627\u0631\u0629<\/td>\n\u2212196\u00b0C to +425\u00b0C, depending on material and seat selection<\/td>\n<\/tr>\n
Cryogenic testing<\/td>\nBS 6364 or project-specified testing requirements<\/td>\n<\/tr>\n
\u0627\u0644\u062a\u0634\u063a\u064a\u0644<\/td>\n\u0630\u0631\u0627\u0639\u060c \u0639\u0644\u0628\u0629 \u062a\u0631\u0648\u0633\u060c \u0645\u0634\u063a\u0644 \u0647\u0648\u0627\u0626\u064a \u0623\u0648 \u0645\u0634\u063a\u0644 \u0643\u0647\u0631\u0628\u0627\u0626\u064a<\/td>\n<\/tr>\n
\u0645\u0648\u0627\u062f \u062a\u0635\u0646\u064a\u0639 \u0627\u0644\u0647\u064a\u0643\u0644<\/td>\nCF8\/F304, CF8M\/F316, CF3\/F304L, CF3M\/F316L or special
\nmaterials on request<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/section>\n
\"Side
Extended-stem construction keeps the operating area above LNG
\npipe insulation.<\/figcaption><\/figure>\n
\n

Which Design Details Matter Most in LNG Service?<\/h2>\n

Extended stem and packing location<\/h3>\n

The extension length must place the packing above the insulation
\nand expected frost line. This helps protect the packing and
\nprovides enough space for the handwheel, gearbox or actuator.<\/p>\n

Low-temperature material toughness<\/h3>\n

The body, stem, ball, bolting and pressure-containing parts must
\nremain suitable at the minimum design temperature. Material
\ncertificates and impact-test requirements should be stated in the
\ninspection plan.<\/p>\n

Seat contraction and leakage control<\/h3>\n

The ball, seat and seal materials contract at different rates
\nduring cooldown. The seat design must maintain contact without
\nproducing excessive operating torque.<\/p>\n

Soft-seat and metal-seat designs should be selected according to
\ntemperature, leakage requirements, operating frequency and fluid
\ncleanliness.<\/p>\n

Body-cavity pressure relief<\/h3>\n

LNG trapped between closed seats can expand as it absorbs heat.
\nThe valve needs an engineered cavity-relief arrangement, such as
\na defined self-relieving seat direction, to prevent unsafe
\npressure buildup.<\/p>\n

\u0645\u062a\u0637\u0644\u0628\u0627\u062a \u0627\u0644\u0633\u0644\u0627\u0645\u0629 \u0645\u0646 \u0627\u0644\u062d\u0631\u0627\u0626\u0642 \u0648\u0645\u0643\u0627\u0641\u062d\u0629 \u0627\u0644\u0643\u0647\u0631\u0628\u0627\u0621 \u0627\u0644\u0633\u0627\u0643\u0646\u0629<\/h3>\n

LNG is flammable. Fire-safe construction and electrical
\ncontinuity may be specified depending on the installation and
\ngoverning standard. The RFQ should identify the exact
\nqualification and certificate required.<\/p>\n<\/section>\n

\n

Where Are Side Entry Cryogenic Ball Valves Used?<\/h2>\n